promisor-remote: fix promisor.quiet to use the correct repository

promisor-remote: fix promisor.quiet to use the correct repository

fetch_objects() reads the promisor.quiet configuration from
the_repository instead of the repo parameter it receives.

This means that when git lazy-fetches objects for a non-main
repository, eg. a submodule that is itself a partial clone opened
via repo_submodule_init(). The submodule's own promisor.quiet
setting is ignored and the superproject's setting is used instead.

Fix by replacing the_repository with repo in the repo_config_get_bool()
call. The practical trigger is git grep --recurse-submodules on a
superproject where the submodule is a partial clone.

Add a test where promisor.quiet is set only in a partial-clone
submodule; a lazy fetch triggered by "git grep --recurse-submodules"
must honor that setting.

Signed-off-by: Trieu Huynh <vikingtc4@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>